diff --git a/inc/caldav-OPTIONS.php b/inc/caldav-OPTIONS.php
index a32660b3..c35992e9 100644
--- a/inc/caldav-OPTIONS.php
+++ b/inc/caldav-OPTIONS.php
@@ -1,9 +1,30 @@
 <?php
   dbg_error_log("OPTIONS", "method handler");
-  header( "Content-type: text/plain");
-//  header( "Allow: OPTIONS, GET, HEAD, POST, PUT, DELETE, TRACE, COPY, MOVE, PROPFIND, PROPPATCH, LOCK, UNLOCK, REPORT, ACL");
-  header( "Allow: ACL, COPY, DELETE, GET, HEAD, LOCK, MKCALENDAR, MKCOL, MOVE, OPTIONS, POST, PROPFIND, PROPPATCH, PUT, REPORT, SCHEDULE, TRACE, UNLOCK");
-//  header( "DAV: 1, 2, 3, access-control, calendar-access");
-//  header( "DAV: 1, 2, 3, calendar-access, calendar-schedule");
-  header( "DAV: 1, 2, access-control, calendar-access, calendar-schedule");
+
+  header( "Content-type: text/plain" );
+  header( "Content-length: 0" );
+
+  /**
+  * As yet we only support quite a limited range of options.  When we see clients looking
+  * for more than this we will work to support them further.  We should probably support
+  * PROPPATCH, because I suspect that will be used.  Also HEAD and POST being fairly standard
+  * should be handled.  COPY and MOVE would seem to be easy also.
+  */
+  header( "Allow: OPTIONS, GET, PUT, DELETE, PROPFIND, REPORT, MKCALENDAR, MKCOL");
+  // header( "Allow: ACL, COPY, DELETE, GET, HEAD, LOCK, MKCALENDAR, MKCOL, MOVE, OPTIONS, POST, PROPFIND, PROPPATCH, PUT, REPORT, SCHEDULE, TRACE, UNLOCK");
+
+  /**
+  * FIXME: WTF is calendar-schedule ??  The CalDAV draft 15 doesn't mention it,
+  * but some CalDAV servers seem to say they do it.  We'll leave it out for now.
+  *
+  * access-control is rfc3744, so we will say we do it, but I doubt if we do it
+  * in all it's glory really.
+  */
+  header( "DAV: 1, 2, access-control, calendar-access");
+  // header( "DAV: 1, 2, access-control, calendar-access, calendar-schedule");
+
+  /**
+  * FIXME: We should only return the 'calendar-access' and 'calendar-schedule' DAV headers for calendar collections.
+  * We should only "Allow" the REPORT method against calendar collections.
+  */
 ?>
\ No newline at end of file